This invention relates to a dispenser which is designed, by the sliding movement of a piston, to suck up a liquid in a vessel such as insecticide, neutral detergent or cosmetic liquid into a cylinder and pressurize the liquid to jet in from an orifice.
With a piston attached to its head and with a cylinder attached to its cap, this type of dispenser is attached to a vessel through the cap. And the dispenser is constructed such that by, for example, depressing the head the piston is lowered, thereby jetting the liquid. That is, by depressing the head, the piston is caused to make a sliding movement and the liquid is thereby jetted. This type of dispenser, therefore, is required to be packed and transported so as to prevent the head from being depressed at a time preceding to the commencement of the actual use. Further, where the dispenser is exhibited in a store, it is necessary to prevent the head from being depressed due to carelessness or fall to permit the emanation of the liquid from the dispenser. Namely, it is demanded that the dispenser be subjected to what is called "virgin-lock" directed to preventing the unnecessary or careless depression of the head at a time preceding to the commencemennt of its actual use. Further, if the dispenser can be packed as compactly as possible when taken in its axial direction, it can be transported with high efficiency, thereby reducing the cost of transportation. Even after the commencement of the actual use, it is demanded that the dispenser be equipped with a locking means, or what is called "child-proof" means, intended to prevent the depression of the head at a time of non-use so as to safeguard children against the possible accidents.
Known is a dispenser of the type wherein a removable virgin seal is provided on the upper part of the head. In this type of dispenser, even if the head is erroneously depressed, it is not actually depressed by being obstructed due to the existence of the virgin seal. This virgin-lock can be released by removing or exfoliating the virgin seal. As an example of this type of dispenser, there is a dispenser of U.S. Pat. No. 3,306,497 (patented on Feb. 28, 1967 and invented by A. Kenney et al). In the dispenser virgin-locked by means of virgin seal, the head can be freely depressed after removal of the virgin seal. Therefore, the dispenser is not made child-proof. Further, the head is usually kept at its raised position and as a result the dispenser can not be compactly packed in its axial direction.
A dispenser has been also proposed which is equipped with a locking means serving both as a virgin-locking means and as a child-proofing means. According to Japanese Patent Publication No. 48-29402 (published on Sept. 10, 1973, the Applicant: Kalmer Incorporated), an externally threaded portion is provided on the outer circumferential surface of the head, while an internally threaded portion is provided on the inner circumferential surface of the cylinder. And by depressing the head and screwing it into the cylinder, the dispenser is virgin-locked and child-proofed. When this screw engagement is released, the head is raised and brought to a depressible position. In the state of screw-engagement, the head is locked at its lowered or depressed position, thereby providing a merit that the dispenser can be packed compactly in its axial direction. When the head is raised and thus located at its depressible position, however, the externally threaded portion of the head is exposed, thereby providing a demerit that the dispenser fails to have a good appearance.